Based on Tokyo VAAC data, SVERT reported that on 7 April an ash plume from Chirinkotan rose to an altitude of 5 km (16,400 ft) a.s.l. and drifted NE. The Aviation Color Code remained at Yellow (on a four-color scale).

Intermittent ash plumes and thermal anomalies June 2013-April 2017, site visit by Russian scientists, August 2015

The remote island of Chirinkotan is in the Northern Kuril Islands at the southern end of the Sea of Okhotsk, about 320 km SW of the tip of Kamchatka, Russia. It is an outlier about 40 km NW of the main Kuril Islands Arc. There have been very few historical observations of activity at Chirinkotan, although there is at least one confirmed 19th century observation of lava flows. A short-lived event that resulted in a small, low-level ash plume-and-gas plume was seen in satellite imagery on 20 July 2004 (Neal et al., 2005). Volcanic activity resumed in mid-2013, with intermittent ash plumes, thermal anomalies, and block lava flows reported through April 2017. The volcano is monitored by the Sakhalin Volcanic Eruption Response Team (SVERT) of the Institute of Marine Geology and Geophysics (Far Eastern Branch, Russian Academy of Science), and aviation alerts are issued by the Tokyo Volcanic Ash Advisory Center (VAAC).

A new eruptive phase began with a likely ash emission on 11 June 2013. Intermittent thermal anomalies and gas-and-steam emissions were reported for the next 12 months, sometimes drifting up to 100 km, usually SE. Renewed thermal anomalies and gas emissions were recorded during clear weather beginning on 21 November 2014. Two ash plumes observed in late July 2015 were the likely sources of fresh ashfall and block lava flows sampled during a visit by Russian geoscientists on 9 August 2015. A gas-and-steam plume on 17 November 2015 was the last activity observed, except for low-level thermal anomalies, until a substantial ash plume was captured in satellite data at 8.8 km altitude over a year later on 29 November 2016. Additional ash plumes were observed in satellite data once in late January, and twice each in March and April 2017.

Activity during May 2013-June 2014. After no reports of activity since July 2004, SVERT observed gas-and-steam emissions in satellite imagery beginning in late May 2013. They raised the Alert Level from Green to Yellow (on the four level Green-Yellow-Orange-Red scale) sometime between 27 May and 10 June. The first likely ash emission was reported on 11 June, followed by a thermal anomaly detected on 13 June. Thermal anomalies continued to be detected by SVERT during June and July 2013. The first MODVOLC thermal alert was reported on 22 July; they were reported monthly after that through 11 December 2013, with several days of multiple-pixel alerts. SVERT also noted thermal anomalies and gas-and-steam emissions during August through December, including plumes drifting 30-60 km SE during 17-19 October, 55-100 km SE during 5-6 November, and more than 50 km SE on 25 November.

From the beginning of January 2014 through early June, persistent thermal anomalies were observed in clear imagery nearly every week by SVERT, along with intermittent steam-and-gas emissions. Several times during March, plumes were observed drifting 80-170 km SE. MODVOLC thermal alerts were reported on 8 February, 4 days in March (four pixels on 8 March), and twice on 27 May. SVERT reported that beginning on 24 May, gas emissions containing ash were detected in satellite images. A decrease in thermal anomalies observed by SVERT led them to lower the Alert Level to Green on 5 June 2014.

Activity during November 2014-July 2015. SVERT raised the Alert Level back to Yellow in late November 2014, citing new thermal anomalies beginning on 21 November followed by intermittent steam-and-gas emissions. A plume was observed drifting 40 km SE on 27 November. A new MODVOLC thermal alert appeared on 4 December. SVERT reported thermal anomalies and diffuse gas-and-steam plumes during December 2014 and January-February 2015. Emissions were detected 3 km above Chirinkotan drifting SE on 5 January 2015. MODVOLC reported two thermal alert pixels on 7 January and one on 10 January.

SVERT briefly lowered the Alert Level to Green between 4 and 20 March when no activity was detected. Thermal anomalies were reported again beginning on 19 March; they were noted weekly along with intermittent gas-and-steam emissions through mid-May when the Alert Level was lowered back to Green again on 19 May.

MODVOLC reported a three-pixel thermal alert on 20 July 2015 (local time). The Tokyo VAAC reported an eruption on 21 July (local time) with an ash plume rising to 3.7 km altitude drifting SE. The plume was observed in satellite imagery for about 2 hours before dissipating. SVERT reported a thermal anomaly and steam-and-gas emissions on 22 July, and the Alert Level was raised to Yellow. Another ash plume was reported by the Tokyo VAAC on 26 July rising to an altitude of 4.6 km and drifting NW for several hours before dissipating.

Expedition during August 2015. Scientists from the Institute of Marine Geology and Geophysics (IMGiG) of the Far Eastern Branch of the Russian Academy of Sciences visited Chirinkotan on 9 August 2015. While there, they observed steaming from a recent blocky lava flow near the coast (figure 3), hiked to the summit, and collected data about volcanic and biological activity on the island. A group of researchers climbed to the edge of the summit crater at 600 m elevation, where clouds prevented clear views of the crater (figure 4), however the strong odor of sulfur and noise from fumarolic activity was noted. The scientists sampled the fresh pyroclastic rocks. When the visibility improved, the depth of the crater was observed to be about 150 m; an extrusive dome in the center had a vent on the top emitting gas.

The upper flank of the volcano was strewn with ash and bombs (from 2-3 cm to several meters in diameter). Scientists observed recently buried and charred living vegetation, and nesting birds freshly killed by volcanic ash and bombs, indicating a very recent event (figure 5). The botanists in the research group noted that all of the vegetation on the upper and middle flanks had been killed 2-3 years ago in a major event, likely during the start of the 2013 eruptive cycle. Ash deposits ranged in thickness from a few centimeters near the coast to 8-15 cm near the summit. During a survey of a pyroclastic flow on the SW coast, scientists noted that it was still hot on the surface (40-60°?) and consisted of block lava, bombs, and volcanic ash (figure 6).

Activity during November 2015-April 2017. As a result of the direct observations of the recent eruption on the island, SVERT raised the Alert Level to Orange on 11 August 2015. There were no further reports available from SVERT until 17 November when gas-and-steam emissions were detected, and the Aviation Color Code was reported as Yellow. SVERT reported on 7 December 2015 that the ACC had been lowered to Green. Although SVERT did not report renewed activity from Chirinkotan until it issued a VONA on 29 November 2016 and raised the Alert Level to Yellow, the MIROVA thermal anomaly detection system indicated intermittent low-level anomalies between late May and early October 2016 (figure 7), indicating a heat source on the island.

Figure 7. MIROVA data of Log Radiative Power at Chirinkotan for the year ending on 31 January 2017 showing a weak but persistent thermal anomaly between late May and early October 2016. Courtesy of MIROVA.

The Tokyo VAAC issued a report of a volcanic ash plume from an eruption on 29 November (local time) 2016. The plume rose to 8.8 km altitude and drifted N. It was observed in satellite imagery for about 9 hours before dissipating. SVERT briefly raised the ACC to Yellow between 29 November and 2 December. They noted that the ash plume was observed drifting 39 km N. A new report of ash emissions came from the Tokyo VAAC on 26 January 2017, with an ash plume at 3.7 km drifting SE observed in the Himawari-8 satellite imagery. SVERT raised the alert level to Yellow on 27 January (UTM) 2017 and also noted ash emissions on 29 January drifting SE to a maximum distance of 105 km. They lowered the Alert Level to Green on 1 February 2017.

A new ash plume was observed by the Tokyo VAAC on 1 March (local time) 2017 at an altitude of 5.5 km. When SVERT raised the Aviation Color Code to Yellow on 2 March, they noted that the plume had drifted 165 km E. They lowered the ACC back to Green on 6 March. The Tokyo VAAC reported a new ash plume at 6.1 km extending SE early on 21 March 2017. SVERT reported the emission at 15 km E of the volcano when they raised the ACC to Yellow a short while later. They noted on 24 March, when they lowered the ACC to Green, that the maximum extent of the ash cloud had been about 50 km SE.

On 31 March 2017, the Tokyo VAAC issued an advisory for an ash plume at 6.7 km altitude drifting E, and SVERT raised the Alert Level to Yellow the next day. They reported the ash plume drifting 165 km NE before dissipating. Another plume on 7 April was observed by the Tokyo VAAC at 3.7 km altitude drifting SE. SVERT reported the plume at 5 km altitude drifting NE. SVERT lowered the ACC to Green on 24 April 2017.

Based on Tokyo VAAC data, SVERT reported that on 7 April an ash plume from Chirinkotan rose to an altitude of 5 km (16,400 ft) a.s.l. and drifted NE. The Aviation Color Code remained at Yellow (on a four-color scale).

Based on Tokyo VAAC satellite data, SVERT reported that on 31 March an ash plume from Chirinkotan rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted 165 km NE. The Aviation Color Code was raised to Yellow (on a four-color scale) on 2 April.

Based on satellite images, SVERT reported that on 21 March an ash plume from Chirinkotan rose to an altitude of 6 km (20,000 ft) a.s.l. and drifted 15 km E. The Aviation Color Code was raised to Yellow (the second lowest on a four-color scale).

Based on satellite images, SVERT reported that on 1 March an ash plume from Chirinkotan rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted 165 km E. The Aviation Color Code remained at Yellow (on a four-color scale).

Based on satellite images, SVERT reported that on 26 and 29 January ash plumes from Chirinkotan rose to an altitude of 3.5 km (11,500 ft) a.s.l. and drifted at most 105 km E and S. The Aviation Color Code remained at Yellow (on a four-color scale).

SVERT reported that on 29 November an ash plume rose from Chirinkotan was visible in satellite images rising to an altitude of 8.8 km (29,000 ft) a.s.l. and drifting 39 km N. The Aviation Color Code was raised to Yellow (on a four-color scale).

SVERT reported that on 17 November gas-and-steam emissions from Chirinkotan were detected in satellite images. Cloud cover prevented views of the volcano during 18-23 November. The Aviation Color Code remained at Yellow.

According to SVERT observers reported a weak eruption at Chirinkotan on 10 August, characterized by block flows and pyroclastic flows that reached the coast. The Aviation Color Code was raised to Orange.

Based on satellite image observations, the Tokyo VAAC reported that a possible eruption at Chirinkotan on 26 July may have produced an ash plume that rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted NW. A subsequent notice the next day stated that ash was observed in images and then dissipated.

Based on satellite image observations, the Tokyo VAAC reported that a possible eruption at Chirinkotan on 21 July may have produced an ash plume that rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted SE. A subsequent notice stated that ash was observed in images and then dissipated. SVERT reported that on 22 July a thermal anomaly over Chirinkotan was detected in satellite images as well as steam-and-gas emissions. The Aviation Color Code was raised to Yellow.

SVERT reported that on 10 May a thermal anomaly over Chirinkotan was detected in satellite images. Cloud cover prevented views of the volcano on the other days during 4-11 May. The Aviation Color Code remained at Yellow.

SVERT reported that on 30 April a thermal anomaly over Chirinkotan was detected in satellite images. Cloud cover prevented views of the volcano on the other days during 27 April-4 May. The Aviation Color Code remained at Yellow.

SVERT reported that during 17-18 April a thermal anomaly over Chirinkotan was detected in satellite images. Cloud cover prevented views of the volcano on the other days during 13-20 April. The Aviation Color Code remained at Yellow.

SVERT reported that on 6 April a thermal anomaly over Chirinkotan was detected in satellite images. Weak gas-and-steam emissions were noted on 8 April. Cloud cover prevented views of the volcano on the other days during 7-13 April. The Aviation Color Code remained at Yellow.

SVERT reported that on 5 April a thermal anomaly over Chirinkotan was detected in satellite images. Cloud cover prevented views of the volcano on the other days during 31 March-6 April. The Aviation Color Code remained at Yellow.

SVERT reported that on 27 March a thermal anomaly over Chirinkotan was detected in satellite images. Cloud cover prevented views of the volcano on the other days during 23-30 March. The Aviation Color Code remained at Yellow.

In a report from 4 March SVERT noted that weak steam-and-gas emissions from Chirinkotan were observed in January and February but that volcanic activity was not currently observed; the Aviation Color Code was lowered to Green.

SVERT reported that weak steam-and-gas emissions from Chirinkotan were detected in satellite images on 6 and 8 February. Cloud cover obscured views on the other days during 2-9 February. The Aviation Color Code remained at Yellow.

SVERT reported that weak steam-and-gas emissions from Chirinkotan were detected in satellite images on 31 January. Cloud cover obscured views on the other days during 26 January-2 February. The Aviation Color Code remained at Yellow.

SVERT reported that weak steam-and-gas emissions from Chirinkotan were detected in satellite images during 13-14 January. A thermal anomaly was visible on 13 and 15 January. The Aviation Color Code remained at Yellow.

SVERT reported that steam-and-gas emissions detected in satellite images rose 3 km above Chirinkotan and drifted SE on 5 January. A thermal anomaly was visible during 8 and 10-11 January. Cloud cover obscured views on the other days during 6-12 January. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was detected in satellite images on 30 December. Cloud cover obscured views on the other days during 29 December-5 January. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was detected in satellite images on 15 and 21 December. Cloud cover obscured views on the other days during 16-22 December. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was detecetd in satellite images during 10-11 and 13-14 December. Cloud cover obscured views on the other days during 8-15 December. The Aviation Color Code remained at Yellow.

SVERT reported that satellite images of Chirinkotan showed a thermal anomaly during 2-5 and 7 December, and diffuse gas-and-steam emissions on 3 December. Cloud cover obscured views on the other days during 1-8 December. The Aviation Color Code remained at Yellow.

SVERT reported that since 21 November a thermal anomaly and increased gas-and-steam emissions at Chirinkotan were detected in satellite images. A thermal anomaly was detected on 25 November, and a diffuse steam-and-gas plume drifted 40 km SE on 27 November. Steam-and-gas emissions were again observed on 28 and 30 November. The Aviation Color Code was raised to Yellow.

SVERT reported that satellite images of Chirinkotan showed diffuse gas-and-steam emissions on 24 March and steam-and-gas plumes drifting 80-170 km SE during 26-27 March. Cloud cover obscured views on the other days during 25-31 March. The Aviation Color Code remained at Yellow.

SVERT reported that a steam-and-gas plume from Chirinkotan was observed in satellite images drifting more than 80 km SE on 20 March. Diffuse steam-and-gas emissions were observed during 21-22 March. Cloud cover obscured views on the other days during 17-19 and 23-24 March. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 10 and 13 March. Steam-and-gas emissions were observed on 10 March and drifted more than 40 km SW on 12 March. Cloud cover obscured views on the other days during 11-17 March. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 25 February and gas-and-steam emissions were observed on 27 February. Cloud cover obscured views on other days during 24 February-3 March. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 20 February. Cloud cover obscured views on other days during 17-24 February. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 12 and 15 February, and steam-and-gas emissions were observed on 16 February. Cloud cover obscured views on other days during 11-17 February. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 8 February, and steam-and-gas emissions were observed on 9 February. Cloud cover obscured views on other days during 4-10 February. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 15 and 17 January. Gas-and-steam emissions were also observed on 17 January. Cloud cover obscured views on the other days during 14-20 January. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 9 and 12 January. Cloud cover obscured views on the other days during 7-13 January. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images during 25-26 December. Cloud cover obscured views on the other days during 23-30 December. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 9, 12, and 15 December. Cloud cover obscured views on the other days during 10-16 December. The Aviation Color Code remained at Yellow.

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 9, 12, and 15 December. Cloud cover obscured views on the other days during 10-16 December. The Aviation Color Code remained at Yellow.

SVERT reported that during 29-31 October, steam-and-gas emissions from Chirinkotan were detected in satellite images; thermal anomalies were also detected during this time. The Aviation Color Code remained at Yellow.

SVERT reported that during 21-25 October steam-and-gas emissions from Chirinkotan were detected in satellite images. A thermal anomaly was detected on 24 October. The Aviation Color Code remained at Yellow.

SVERT reported that during 17-19 October a thermal anomaly from Chirinkotan was detected in satellite images along with gas-and-steam emissions drifting 30-60 km SE. Cloud cover prevented observations on the other days during 14-21 October. The Aviation Color Code remained at Yellow.

Based on analysis of satellite images, SVERT reported that a thermal anomaly and gas-and-steam emissions from Chirinkotan were observed on 5 and 9 August. A thermal anomaly was visible on 7 August, and possible gas-and-steam emissions were observed on 7 and 8 August. The Aviation Color Code remained at Yellow.

Based on analysis of satellite images, SVERT reported that a thermal anomaly from Chirinkotan was observed on 22 July. Weak steam-and-gas emissions and a weak thermal anomaly were observed on 25 July. The Aviation Color Code remained at Yellow.

Based on analysis of satellite images, SVERT reported that a thermal anomaly and possible weak steam-and-gas emissions from Chirinkotan were observed on 16 and 18 July. The Aviation Color Code remained at Yellow.

Based on analysis of satellite images, SVERT reported that weak steam-and-gas emissions from Chirinkotan were observed on 12 July and a thermal anomaly was detected during 12-13 July. The Aviation Color Code remained at Yellow.

Based on analysis of satellite images, SVERT reported that steam-and-gas emissions from Chirinkotan were observed on 3 July and a thermal anomaly was detected on 4 July. The Aviation Color Code remained at Yellow.

Information is preliminary and subject to change. All times are local (unless otherwise noted)

In April 1979, an eruption began from Chirinkotan volcano, which forms an isolated, uninhabited island about 3 km in diameter. Block lava flowed down the SSW flank in April and May. Ash explosions occurred regularly during the summer of 1979 and explosive activity increased in October. In January and April 1980, moderate explosions occurred 1-2 times per hour.

Chirinkotan was observed from the air 11, 12, and 31 October, and 2 November. A thick gas and ash column reached 700-800 m above the crater, and drifted 6-8 km downwind on 11 October. Intense gas emission occurred throughout the crater. On 12 October gas emission was less intense but a gas cloud reached 400-600 km high and was 3-4 km long despite a strong wind. By 31 October fumarolic activity had diminished significantly. On the E crater slope a few groups of large fumaroles were observed. A gas plume 200 m in diameter was 250 m high and 800-900 m long. Flank ashfall had been covered by snow that fell 12-13 October. Activity was similar on 2 November.

In 1979-1980, an eruption at Chirinkotan included a series of ash explosions and a lava flow (SEAN 05:06). In October and November 1986, airborne observers saw a column of thick gas and ash, and then fumarolic activity (SEAN 12:04). This report discusses events during 2013 through April 2014. The location of Chirinkotan in the Kuril Islands is shown in figure 1.

According to the Sakhalin Volcanic Eruption Response Team (SVERT), gas-and-steam emissions occurred frequently in 2013-2014 (table 1). The Aviation Color Code was Green on 24-25 May 2013, when emissions were first reported, but raised to Yellow during early June 2013, where it has remained through April 2014, the end of this report. The volcano was often obscured by clouds.

According to the U.S. Geological Survey, an M 8.3 earthquake occurred on 24 May 2013 beneath the Sea of Okhotsk, at a point is 656 km N of the volcano. The focal depth of the earthquake was ~ 600 km. The first reported gas-and-steam emission from Chirinkotan, which is in the Sea of Okhotsk, was on 24-25 May, suggesting a possible link between the two events.

Table 1. SVERT-reported dates on which gas-and-steam emissions were observed from 24 May 2013 through 30 April 2014, based on analysis of satellite images. Thermal alerts detected by SVERT and the MODVOLC satellite thermal alert system are also noted.

This Bulletin report discusses activity at Chirinkotan from May 2014 to late-April 2015. The information presented here was primarily sourced from the Sakhalin Volcanic Eruptions Response Team (SVERT). SVERT is in charge of monitoring volcanic activity within the Kuril Islands from Onekotan in the N to Kunashir in the S (figure 2). The volcano also forms an island of the same name. Figure 1 in BGVN 38:12 provides a view of Chirinkotan’s location within the Kuril Islands.

Our last Bulletin report (BGVN 38:12) recorded Chirinkotan activity that occurred from May 2013 to April 2014. During that interval, gas-and-steam emissions and thermal alerts were frequently observed and reported (table 1 in BGVN 38:12).

Figure 2. Maps highlighting the location of Chirinkotan, within the Kuril Islands. On the larger map, Chirinkotan is represented by a red dot directly above the label "Chirinkotan." The map also shows the other islands of the Kuril archipelago, which are located between the Kamchatka Peninsula (Russia, top center) and Hokkaido (Japan, lower left). Also marked on this map are appoximate seafloor convergence rates (arrows) and the location of the trench's E margin (heavy dashed line). The index map, in the top left corner, shows the general area in which the Kuril Islands are located. ‘KC’ represents the Kamchatka Current and ‘SWC’ represents the Soya warm current. Image taken from Belousov and others (2009).

May 2014 to late-April 2015. Due to similarities between Chirinkotan’s activity from May 2014 through late-April 2015 and May 2013-April 2014 (BGVN 38:12), we once again use a table to summarize Chirinkotan’s activity.

Due to their inaccessibility, SVERT relies on satellite monitoring to monitor volcanic activity within the Kuril Islands. On the basis of those observations, SVERT often reported thermal anomalies and gas-and-steam emissions at Chirinkotan during this reporting interval (May 2014 to late April 2015). SVERT frequently reported that clouds obscured views of Chirinkotan, which halted collection of satellite data.

SVERT also reports Chirinkotan’s Aviation Color Code (ACC). The ACC is a four color scale used by some volcano observatories and the aviation community to communicate volcanic-ash hazards of a volcano. The colors in order of increasing volcanic activity are Green, Yellow, Orange and Red.

In an overview, the ACC stood at Yellow during the following periods: May 2014 to the beginning of June 2014; late November 2014 to late February 2015; and from mid-March to late April 2015. SVERT reported Chirinkotan’s ACC as Green during June to late November 2014 and early March 2015.

Table 2 summarizes available SVERT data on Chirinkotan’s activity. The table is divided into two columns labeled Date and Comments. The Date column refers to the week during which Chirinkotan activity was observed or reported by SVERT. The Comments column details Chirinkotan’s ACC and what activity occurred at Chirinkotan on a particular day or during a particular week.

Table 2. Table condensing Chirinkotan’s activity and cases where cloud cover hindered observations between May 2014 and late April 2015. The information in the table was observed in satellite data by SVERT personnel. Bulletin editors gathered this information from available SVERT material (generally published on the end date of the date ranges in the left column).

Intermittent ash plumes and thermal anomalies June 2013-April 2017, site visit by Russian scientists, August 2015

The remote island of Chirinkotan is in the Northern Kuril Islands at the southern end of the Sea of Okhotsk, about 320 km SW of the tip of Kamchatka, Russia. It is an outlier about 40 km NW of the main Kuril Islands Arc. There have been very few historical observations of activity at Chirinkotan, although there is at least one confirmed 19th century observation of lava flows. A short-lived event that resulted in a small, low-level ash plume-and-gas plume was seen in satellite imagery on 20 July 2004 (Neal et al., 2005). Volcanic activity resumed in mid-2013, with intermittent ash plumes, thermal anomalies, and block lava flows reported through April 2017. The volcano is monitored by the Sakhalin Volcanic Eruption Response Team (SVERT) of the Institute of Marine Geology and Geophysics (Far Eastern Branch, Russian Academy of Science), and aviation alerts are issued by the Tokyo Volcanic Ash Advisory Center (VAAC).

A new eruptive phase began with a likely ash emission on 11 June 2013. Intermittent thermal anomalies and gas-and-steam emissions were reported for the next 12 months, sometimes drifting up to 100 km, usually SE. Renewed thermal anomalies and gas emissions were recorded during clear weather beginning on 21 November 2014. Two ash plumes observed in late July 2015 were the likely sources of fresh ashfall and block lava flows sampled during a visit by Russian geoscientists on 9 August 2015. A gas-and-steam plume on 17 November 2015 was the last activity observed, except for low-level thermal anomalies, until a substantial ash plume was captured in satellite data at 8.8 km altitude over a year later on 29 November 2016. Additional ash plumes were observed in satellite data once in late January, and twice each in March and April 2017.

Activity during May 2013-June 2014. After no reports of activity since July 2004, SVERT observed gas-and-steam emissions in satellite imagery beginning in late May 2013. They raised the Alert Level from Green to Yellow (on the four level Green-Yellow-Orange-Red scale) sometime between 27 May and 10 June. The first likely ash emission was reported on 11 June, followed by a thermal anomaly detected on 13 June. Thermal anomalies continued to be detected by SVERT during June and July 2013. The first MODVOLC thermal alert was reported on 22 July; they were reported monthly after that through 11 December 2013, with several days of multiple-pixel alerts. SVERT also noted thermal anomalies and gas-and-steam emissions during August through December, including plumes drifting 30-60 km SE during 17-19 October, 55-100 km SE during 5-6 November, and more than 50 km SE on 25 November.

From the beginning of January 2014 through early June, persistent thermal anomalies were observed in clear imagery nearly every week by SVERT, along with intermittent steam-and-gas emissions. Several times during March, plumes were observed drifting 80-170 km SE. MODVOLC thermal alerts were reported on 8 February, 4 days in March (four pixels on 8 March), and twice on 27 May. SVERT reported that beginning on 24 May, gas emissions containing ash were detected in satellite images. A decrease in thermal anomalies observed by SVERT led them to lower the Alert Level to Green on 5 June 2014.

Activity during November 2014-July 2015. SVERT raised the Alert Level back to Yellow in late November 2014, citing new thermal anomalies beginning on 21 November followed by intermittent steam-and-gas emissions. A plume was observed drifting 40 km SE on 27 November. A new MODVOLC thermal alert appeared on 4 December. SVERT reported thermal anomalies and diffuse gas-and-steam plumes during December 2014 and January-February 2015. Emissions were detected 3 km above Chirinkotan drifting SE on 5 January 2015. MODVOLC reported two thermal alert pixels on 7 January and one on 10 January.

SVERT briefly lowered the Alert Level to Green between 4 and 20 March when no activity was detected. Thermal anomalies were reported again beginning on 19 March; they were noted weekly along with intermittent gas-and-steam emissions through mid-May when the Alert Level was lowered back to Green again on 19 May.

MODVOLC reported a three-pixel thermal alert on 20 July 2015 (local time). The Tokyo VAAC reported an eruption on 21 July (local time) with an ash plume rising to 3.7 km altitude drifting SE. The plume was observed in satellite imagery for about 2 hours before dissipating. SVERT reported a thermal anomaly and steam-and-gas emissions on 22 July, and the Alert Level was raised to Yellow. Another ash plume was reported by the Tokyo VAAC on 26 July rising to an altitude of 4.6 km and drifting NW for several hours before dissipating.

Expedition during August 2015. Scientists from the Institute of Marine Geology and Geophysics (IMGiG) of the Far Eastern Branch of the Russian Academy of Sciences visited Chirinkotan on 9 August 2015. While there, they observed steaming from a recent blocky lava flow near the coast (figure 3), hiked to the summit, and collected data about volcanic and biological activity on the island. A group of researchers climbed to the edge of the summit crater at 600 m elevation, where clouds prevented clear views of the crater (figure 4), however the strong odor of sulfur and noise from fumarolic activity was noted. The scientists sampled the fresh pyroclastic rocks. When the visibility improved, the depth of the crater was observed to be about 150 m; an extrusive dome in the center had a vent on the top emitting gas.

The upper flank of the volcano was strewn with ash and bombs (from 2-3 cm to several meters in diameter). Scientists observed recently buried and charred living vegetation, and nesting birds freshly killed by volcanic ash and bombs, indicating a very recent event (figure 5). The botanists in the research group noted that all of the vegetation on the upper and middle flanks had been killed 2-3 years ago in a major event, likely during the start of the 2013 eruptive cycle. Ash deposits ranged in thickness from a few centimeters near the coast to 8-15 cm near the summit. During a survey of a pyroclastic flow on the SW coast, scientists noted that it was still hot on the surface (40-60°?) and consisted of block lava, bombs, and volcanic ash (figure 6).

Activity during November 2015-April 2017. As a result of the direct observations of the recent eruption on the island, SVERT raised the Alert Level to Orange on 11 August 2015. There were no further reports available from SVERT until 17 November when gas-and-steam emissions were detected, and the Aviation Color Code was reported as Yellow. SVERT reported on 7 December 2015 that the ACC had been lowered to Green. Although SVERT did not report renewed activity from Chirinkotan until it issued a VONA on 29 November 2016 and raised the Alert Level to Yellow, the MIROVA thermal anomaly detection system indicated intermittent low-level anomalies between late May and early October 2016 (figure 7), indicating a heat source on the island.

Figure 7. MIROVA data of Log Radiative Power at Chirinkotan for the year ending on 31 January 2017 showing a weak but persistent thermal anomaly between late May and early October 2016. Courtesy of MIROVA.

The Tokyo VAAC issued a report of a volcanic ash plume from an eruption on 29 November (local time) 2016. The plume rose to 8.8 km altitude and drifted N. It was observed in satellite imagery for about 9 hours before dissipating. SVERT briefly raised the ACC to Yellow between 29 November and 2 December. They noted that the ash plume was observed drifting 39 km N. A new report of ash emissions came from the Tokyo VAAC on 26 January 2017, with an ash plume at 3.7 km drifting SE observed in the Himawari-8 satellite imagery. SVERT raised the alert level to Yellow on 27 January (UTM) 2017 and also noted ash emissions on 29 January drifting SE to a maximum distance of 105 km. They lowered the Alert Level to Green on 1 February 2017.

A new ash plume was observed by the Tokyo VAAC on 1 March (local time) 2017 at an altitude of 5.5 km. When SVERT raised the Aviation Color Code to Yellow on 2 March, they noted that the plume had drifted 165 km E. They lowered the ACC back to Green on 6 March. The Tokyo VAAC reported a new ash plume at 6.1 km extending SE early on 21 March 2017. SVERT reported the emission at 15 km E of the volcano when they raised the ACC to Yellow a short while later. They noted on 24 March, when they lowered the ACC to Green, that the maximum extent of the ash cloud had been about 50 km SE.

On 31 March 2017, the Tokyo VAAC issued an advisory for an ash plume at 6.7 km altitude drifting E, and SVERT raised the Alert Level to Yellow the next day. They reported the ash plume drifting 165 km NE before dissipating. Another plume on 7 April was observed by the Tokyo VAAC at 3.7 km altitude drifting SE. SVERT reported the plume at 5 km altitude drifting NE. SVERT lowered the ACC to Green on 24 April 2017.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Synonyms

Tirinkotan | Chirinkutan | Cherinkutan

Basic Data

Volcano Number

Last Known Eruption

Elevation

LatitudeLongitude

290260

2017 CE

724 m / 2375 ft

48.98°N
153.48°E

Volcano Types

Stratovolcano
Caldera
Pyroclastic cone

Rock Types

MajorAndesite / Basaltic Andesite
Dacite

Tectonic Setting

Subduction zoneIntermediate crust (15-25 km)

Population

Within 5 kmWithin 10 kmWithin 30 kmWithin 100 km

0
0
0
6

Geological Summary

The small, mostly unvegetated 3-km-wide island of Chirinkotan occupies the far end of an E-W-trending volcanic chain that extends nearly 50 km west of the central part of the main Kuril Islands arc. It is the emergent summit of a volcano that rises 3000 m from the floor of the Kuril Basin. A small 1-km-wide caldera about 300-400 m deep is open to the SW. Lava flows from a cone within the breached crater reached the shore of the island. Historical eruptions have been recorded since the 18th century. Lava flows were observed by the English fur trader Captain Snow in the 1880s.

References

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography.

Deformation History

There is no Deformation History data available for Chirinkotan.

Emission History

There is no Emissions History data available for Chirinkotan.

Photo Gallery

The small, mostly unvegetated 3-km-wide island of Chirinkotan is the emergent summit of a volcano that rises 3000 m from the floor of the Kuril Basin. Submarine terraces are lacking around the island, suggesting the edifice is of Holocene age. Chirinkotan lies at the far end of an E-W-trending volcanic chain that extends nearly 50 km west of the central part of the main Kuril Islands arc. Historical eruptions have been recorded at Chirinkotan since the 18th century, including one observed by the English fur trader Captain Snow.

Smithsonian Sample Collections Database

Affiliated Sites

The DECADE portal, still in the developmental stage, serves as an example of the proposed interoperability between The Smithsonian Institution's Global Volcanism Program, the MAGA Database, and the EarthChem Geochemical Portal. The Deep Earth Carbon Degassing (DECADE) initiative seeks to use new and established technologies to determine accurate global fluxes of volcanic CO2 to the atmosphere, but installing CO2 monitoring networks on 20 of the world's 150 most actively degassing volcanoes. The group uses related laboratory-based studies (direct gas sampling and analysis, melt inclusions) to provide new data for direct degassing of deep earth carbon to the atmosphere.

WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.

Middle InfraRed Observation of Volcanic Activity (MIROVA) is a near real time volcanic hot-spot detection system based on the analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) data. In particular, MIROVA uses the Middle InfraRed Radiation (MIR), measured over target volcanoes, in order to detect, locate and measure the heat radiation sourced from volcanic activity.

Using infrared satellite Moderate Resolution Imaging Spectroradiometer (MODIS) data, scientists at the Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, developed an automated system called MODVOLC to map thermal hot-spots in near real time. For each MODIS image, the algorithm automatically scans each 1 km pixel within it to check for high-temperature hot-spots. When one is found the date, time, location, and intensity are recorded. MODIS looks at every square km of the Earth every 48 hours, once during the day and once during the night, and the presence of two MODIS sensors in space allows at least four hot-spot observations every two days. Each day updated global maps are compiled to display the locations of all hot spots detected in the previous 24 hours. There is a drop-down list with volcano names which allow users to 'zoom-in' and examine the distribution of hot-spots at a variety of spatial scales.

EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).